Space shuttle astronauts flew the aircraft to practice landing approaches to runways at Kennedy Space Center in Florida, at Edwards and at White Sands Space Harbor in New Mexico during the shuttle program's more than 30-year history. The modified G-IIs were capable of simulating flying characteristics of the unpowered space shuttles during the shuttles' steep final approach to landing.

With the conclusion of the shuttle program, all four training aircraft are being retired at various NASA facilities around the country.